Tag Archives: Holes

A & B Tip 9 – drilling holes 3 – counterbores

9 Replies

In this series of posts, I’ll be providing tips that show how to do something in both AutoCAD and BricsCAD, hence A & B.

The Series

The idea behind this series is to provide useful information for several sorts of reader:

  1. AutoCAD users.
  2. BricsCAD users.
  3. People in the process of transitioning from AutoCAD to BricsCAD and who need to know what to do differently (if anything).
  4. People considering transitioning from AutoCAD to BricsCAD and who want to know about the differences and similarities.

Counterbored holes

This post continues to explain more about how to put holes in your 3D models. In this post I’ll be describing how to construct counterbored holes. Hint: the most efficient method is described last.

I’m going to start with this model and use different methods to create three counterbored diameter 10 holes that go through the block, each with a diameter 20 x 18 deep counterbore. I’ve placed circles of diameter 10 and 20 in place to indicate where the holes are going to go, and in some cases to act as the basis for extrusion.

If you’re unsure about how to locate these circles in exactly the right spots in 3D space, see my earlier drilling holes posts, part 1 and part 2.

Extruding circles

Assuming we have appropriate circles to work with, we can extrude them to create cylinders, then subtract them. This works in basically the same in both AutoCAD and BricsCAD, but there are differences:

AutoCAD BricsCAD
Invoke the EXTRUDE command:
 Invoke the EXTRUDE command:
Select the inner circle and press Enter to complete the selection process:
 Select the inner circle and press Enter to complete the selection process:
Move your cursor down and click when the extrusion goes beyond the bottom of the block:
 Enter a negative number that equals or exceeds 100 (the thickness of the block):
If you just pick a point as per AutoCAD, the extrusion will go up rather than down. It’s also possible to point to the direction and amount to extrude by using the Direction subcommand and picking two points, for example a top and bottom corner of the solid.
Repeat the above process for the second circle, but this time specify an extrusion height of 18 while the cursor is located such that the extrusion is going down rather than up:
 Repeat the above process for the second circle, but this time specify an extrusion height of -18. It has to be negative, otherwise the extrusion will go up even if you’re pointing down (unlike AutoCAD).

We’ll subtract these cylinders later.

Drawing cylinders

You can draw cylinders to subtract without needing construction circles. In this case one of the circles is just used to help locate the cylinder center point, but you can use other methods that involve no construction geometry instead, as explained in my first drilling holes post.

AutoCAD BricsCAD
Invoke the CYLINDER command (Solid, not Surface):
 Invoke the CYLINDER command (Solids, not Meshes):
Locate the center of the cylinder, in this case using the center object snap:
 Locate the center of the cylinder, in this case using the center entity snap:
Enter a radius of 5:
 Enter a radius of 5:
Move your cursor down and click when the extrusion goes beyond the bottom of the block:
 Move your cursor down and click when the extrusion goes beyond the bottom of the block:
Repeat the above process for the second cylinder, but this time specify a height of 18 while the cursor is located such that the extrusion is going down rather than up:
 Repeat the above process for the second cylinder, but this time specify a height of -18:

Subtracting the cylinders

We can subtract all four cylinders at once to create two of the counterbored holes. This process is the same in both applications.

AutoCAD BricsCAD
Invoke the SUBTRACT command:
 Invoke the SUBTRACT command:
Select the main solid as the object to subtract from and press Enter to complete that selection. Then select the cylinders to remove. This is easiest with an implied window. Pick a corner point containing no objects, starting on the left. Then pick the opposite corner to the right.
Press Enter to complete that selection and the command.		 Select the main solid as the object to subtract from and press Enter to complete that selection. Then select the cylinders to remove. This is easiest with an implied window. Pick a corner point containing no objects, starting on the left. Then pick the opposite corner to the right.
Press Enter to complete that selection and the command.
End result:
 End result:

Note that the first method replaces the circles with cylinders. The second method only uses the circles to help locate the center; they don’t really need to be there at all and are ignored.

Presspulling or Push/pulling

As described before, planar objects such as circles can be extruded by presspulling them. We’ll use that method to create the third counterbored hole. In this case, the operations differ somewhat between AutoCAD and BricsCAD.

AutoCAD BricsCAD
Hold down Ctrl+Shift+E to turn on dynamic presspull mode, hover over the space between the two circles and pick:
 Hover over the inner circle. You should see the Quad Cursor appear, suggesting a push/pull operation. Pick the icon to accept that operation:
Now you can release Ctrl_Shift+E. Move your cursor down and enter 18:
 Move your cursor down beyond the bottom of the block and pick.

Note the on-screen reminder that you can hit the Ctrl key to switch between several different types of push/pull operations. We can ignore this because in this case we want to use the default. However, it’s worth noting that this feature exists because it’s very handy.
Hold down Ctrl+Shift+E to turn on dynamic presspull mode, hover over the inside of the inner circle and pick. Release Ctrl+Shift+E, move your cursor down beyond the bottom of the block and pick:
 Hover over the outer circle and pick the push/pull icon on the Quad Cursor. You could enter a height of -18, but in this case there’s a handy nearby hole counterbored to the correct depth and we can just pick the center of that instead:
In the AutoCAD presspull end result, the circles are left behind so if you don’t want them you will need to erase them.
Note also that your UCS origin is changed by this operation even if dynamic UCS is turned off. To restore it, use UCS Previous or use the UCS menu under the ViewCube to change it to World or any other named UCS:
 In the BricsCAD push/pull end result, the circles are converted to holes so no more action is required. No UCS restoration is necessary.

Summary

Assuming you have construction circles in place, presspulling is the most efficient of the three methods in AutoCAD, even allowing for the tidy-up required at the end.

BricsCAD’s Quad-based push/pull operation is the most efficient method of the lot. Hover, pick, pick and hover, pick, pick is enough to create a counterbored hole.

Next: countersunk holes.

A & B Tip 8 – drilling holes 2

2 Replies

In this series of posts, I’ll be providing tips that show how to do something in both AutoCAD and BricsCAD, hence A & B.

The Series

The idea behind this series is to provide useful information for several sorts of reader:

  1. AutoCAD users.
  2. BricsCAD users.
  3. People in the process of transitioning from AutoCAD to BricsCAD and who need to know what to do differently (if anything).
  4. People considering transitioning from AutoCAD to BricsCAD and who want to know about the differences and similarities.

Drilling holes

This post continues to explain more about how to put holes in your 3D models. More than one method involves starting with a planar object (e.g. a circle for a cylindrical hole), but it needs to be in the right spot and in the right plane. The most efficient way of drawing an object in a given plane, where that plane exists on a 3D solid, is to use Dynamic UCS.

Dynamic UCS

First, we need to make sure Dynamic UCS is turned on. In AutoCAD, the Dynamic UCS icon looks like this:

If that’s not visible, you may need to make it visible using the hamburger menu on the far right of the status bar:

In BricsCAD, the text-based toggle (like the one AutoCAD users have been asking to return ever since it was removed a few releases ago) is DUCS:

Just in case that toggle’s not visible, there’s a list of toggles in a menu at the bottom right of the BricsCAD user interface, too:

You can also toggle the Dynamic UCS status in both applications using F6.

Having established that DUCS is on, invoke the Circle command. Hover over the plane that’s on the left as we’re looking at it, thus:

You are now working in a temporary UCS with an origin point in one corner of the 3D solid’s face, and as you move around you can use the coordinate display to get an idea of where the coordinates lie. If I enter -100,50 this is used in relation to the origin of the dynamic UCS and I will get a circle here:

Things work in a similar way in BricsCAD. You don’t get the on-screen dynamic coordinates, but you can still see them in the status bar and you do get a UCS icon that shows you how the temporary UCS is aligned. If you move your cursor around, you will be able to obtain different UCS alignments and easily see where the origin is and which way X and Y are oriented:

With this visual information and the dynamic UCS shown above, you can enter 100,50 to place the circle in the same spot as in AutoCAD.

Now we have our circle (and it could just as easily be a filleted rectangle or any other shape), we could extrude it as described in my previous post. Instead, let’s push and pull it into shape as described below.

Presspulling or Push/pulling

Instead of using the EXTRUDE command, planar objects can be extruded by presspulling them. Before drilling some holes, I should explain that there are several differences (some subtle) between extrusion and presspull:

  • Extruding replaces the original objects whereas presspulling leaves them in place and creates new objects.
  • The EXTRUDE command expects you to select objects to extrude; the PRESSPULL command allows you to point within an enclosed area. Depending on what you’re starting with, one command will be more suitable than the other.
  • Extruding an area enclosed by individual objects (e.g. lines) extrudes the objects into planar surfaces. Presspulling such an enclosed area results in a 3D solid being created based on an extrusion of the enclosed area.
  • An EXTRUDE of an enclosed planar object (e.g. circle, closed polyline) creates a 3D object. PRESSPULL can also do this, but when the planar object lies on the surface of a 3D solid, it can also create a hole in that solid.
  • Both commands can be used on faces of 3D solids; EXTRUDE will create a new solid based on an extrusion of that face and PRESSPULL will modify the original solid.

Presspulling in AutoCAD

In AutoCAD, you can use the PRESSPULL command:

Alternatively, you can use Ctrl+Shift+E to invoke presspulling: hold all three keys down and point within an enclosed area. Here’s an example. A circle has been drawn on the left vertical surface of our solid. Hold down Ctrl+Shift+E together and pick the interior of the circle. Let go of the keys and move your mouse to the right:

Pick a point beyond the extents of the solid. A hole is automatically created in the solid without having to explicitly subtract it, thus:

User actions required: a three-key combination and two picks. Note that the original circle is still present and if you don’t want it there you will need to erase it.

Push/Pulling in BricsCAD

In BricsCAD, there is no PRESSPULL command. Instead, the closest equivalent command name is DMPUSHPULL (the DM stands for Direct Modeling).

This command expects to work on faces of 3D solids, which is not exactly what we’re after for drilling holes. Instead, we use the DMEXTRUDE command. Now it might seem confusing that there are different commands to use for similar things, but in practice that doesn’t matter. That’s because we can just use the Quad Cursor and really not care what the underlying command is called. If you hover over a 3D solid’s face, the Quad Cursor gives you the options you need for dealing with that, and if you hover over a circle you are given the appropriate options for that instead.

Here’s the same example as above, this time done in BricsCAD. Hover over an object that defines an enclosed area, in this case our circle:

The Quad Cursor uses AI technology to initially provide the option that it thinks you’re most likely to use with that object under the current circumstances. I find it’s remarkably good at guessing what you want to do. If it’s wrong, you can get at a whole bunch of other options with a bit more hovering, but in this case it’s right; we do want to extrude the circle. Pick that icon, move over to the right and pick. That will create the hole:

User actions required: a hover and two picks. Again, the original circle remains behind and will need to be erased if you don’t want it left hanging around.

What about more complex holes? There are more tips and tricks coming, so watch this space.

A & B Tip 7 – drilling holes 1

2 Replies

In this series of posts, I’ll be providing tips that show how to do something in both AutoCAD and BricsCAD, hence A & B.

The Series

The idea behind this series is to provide useful information for several sorts of reader:

  1. AutoCAD users.
  2. BricsCAD users.
  3. People in the process of transitioning from AutoCAD to BricsCAD and who need to know what to do differently (if anything).
  4. People considering transitioning from AutoCAD to BricsCAD and who want to know about the differences and similarities.

Drilling holes

This post explains how to put holes in your 3D models. This post will cover some fairly straightforward topics but I intend to cover more involved details in future posts. I’ll assume you have a basic understanding of creating 3D primitives and the boolean operations (union, subtract and intersect). I will be using the 3D Modeling workspace in both AutoCAD and BricsCAD. I’m going to start with the dynamic UCS feature turned off and the 2D Wireframe visual style.

Vertical cylinder subtraction

Let’s take the simplest case. You have a solid and you just want to place a cylindrical hole in a known location that you already have geometry you can snap to. For example, you want to drill a DIA 40 hole right through this part, using the centerlines shown:

Start with the CYLINDER command:

AutoCAD BricsCAD

Pick the intersection of the two centerlines, enter a radius of 20 and a height of 100. You don’t have to be precise with the height, you can just point to any height that’s over 100:

To create the hole, use the SUBTRACT command:

AutoCAD BricsCAD

With this command it’s important to select the objects in the right order. Select the object(s) you’re substantiating from first, then press Enter to finish the selection process for those objects. Then select the object(s) you’re subtracting and press Enter to finish that selection process. That will give you your hole (temporarily switched to X-Ray visual style for clarity):

Extruding a circle

Instead of creating the cylinder diectly, you can instead extract a circle. This is an extra step if you don’t already have a circle of the right size in the right place, but less work if you do. For example, if you’re converting a 2D drawing to a 3D model, you’ll probably have the circle already.

Invoke the EXTRUDE command:

AutoCAD BricsCAD

Select the circle, press Enter to finish the selection (because you can extrude several objects at once) and specify a height of at least 100, as with the CYLINDER command. Subtract the resultant cylinder and you’re done.

It’s important to note that extrusions work perpendicular to the plane of the object(s) being extruded. In this case the cylinder is created vertically because the circle lies flat (in terms of the World Coordinate System). If you have a circle lying in a different plane, the extrusion will be perpendicular to that plane. For example, here a circle that lies in a vertical plane is being extruded horizontally:

Drawing a circle in the other planes

That’s all well and good if you have a circle in the right plane, but what if you need to draw one? You have several alternatives.

One method is to draw your circle in whatever plane you like, then use the ALIGN command to move it into place. That works, but it’s not that efficient.

Alternatively, you can change your UCS to align with your desired plane, and then just draw your circle. That can be fiddly, but if you have a handy solid object containing the plane you want to draw in, you can use the UCS command’s OBject option (hot tip: E for Entity does the same thing). By carefully hovering over the plane, you can set up your desired UCS with one click and a lot less tiresome fiddling around than trying to work out what the other (somewhat arcane) options of the UCS command all mean. Here, the UCS command’s OBject option is shown in action:

Note that this is an example of one of the very few things that works in AutoCAD but not BricsCAD. The UCS command’s OBject (and Entity) option exists, but you can’t use it to align a UCS with a solid’s face. You can, however, use the UCS command’s Face option. That exists in both applications, but I prefer the way it works in BricsCAD where the origin of the UCS is placed in one corner of the face with no further interaction required. In AutoCAD, the default is to place the UCS origin at some random point you used to select the face so if you need to locate points precisely there is a bit more messing around required.

Upshot: Use UCS E in AutoCAD and UCS F in BricsCAD.

In any case, there are other, more efficient ways to skin this particular cat. In my view, the most efficient way of drawing an object in a given plane, where that plane exists on a 3D solid, is to use Dynamic UCS. I’ll explain that, and how to push and pull your holes into submission, in the next post.